1. Field of the invention
The present invention relates to a processing unit and a system including a plurality of the processing units and more particularly to a system including, for example, a plurality of electronic photo type printers wherein an overload of the power source is prevented.
2. Description of the Related Art
In a system wherein one power source supplies the power to a plurality of image processors, the connection by which the total of the respective, rated currents of the plurality of image processors exceeds the allowable current of the power source is not usually executed. If, for example, the total of the rated currents of the plurality of image processors is less than the allowable current of the power source and, by the addition of another image processor, the total of the rated currents exceeds the allowable current of the power source, the result is that the power source is disconnected by the over current condition, and the possibility thus occurs of the cessation of all the functions of the connected image processors. Generally the allowable current from a power supply terminal (outlet or the like) is about 15 amperes. If the connection of a plurality of image processors, each having a rated current of 8 amperes, is desired, the connection of more than one is dangerous for the above reason. At a time when information processing is popular, the above limitation of the connection of the processors is very inconvenient.